The present invention relates to a polar relay and, more particularly, to a slim polar relay having structural elements arranged side by side on a base which is made of an insulating material.
Usually a polar relay includes at least one permanent magnet and a winding as electromagnetic drive means. An armature is moved by the magnetic operation of the electromagnetic drive means to move contact members into and out of engagement. A characteristic feature of the operation of a polar relay is that it is capable of holding the contact members in or out of engagement either in a monostable mode or in a bistable mode, depending upon the arrangement of the electromagnetic drive means. This type of polar relay finds various applications such as to communications equipments and domestic instruments (television sets, air conditioners, etc.).
Concerning the application to the communications equipments in which the trend to smaller and more integrated designs is ever increasing, it is desirable that the polar relay be provided with a shape and size which is feasible for installation on a printed circuit board together with very small electronic parts, occupying a minimum of space on the circuit board. In an ordinary communications equipment, various circuit parts are loaded on a printed circuit board to constitute a package and a plurality of such packages are mounted side by side on a package shelf. Among all the dimensions of a polar relay, therefore, the height requires a special consideration to set up a flat configuration. Indeed, various flat polar relays have already been proposed.
Meanwhile, where a polar relay is applied to a domestic instrument, particularly a television set or an air conditioner, a slim configuration is desirable rather than the flat configuration in view of effective utilization of space. Tendency in the field of such domestic instruments is to mount on a printed circuit board a capacitor having a large capacity and other elements having relatively large heights, requiring a polar relay to occupy a smallest possible area on the printed circuit board. A larger circuit switching capacity is another important consideration in the application of a polar relay to a domestic instrument. A polar relay fulfilling all these considerations has not been developed yet.